Vacuum cleaner fan assembly

ABSTRACT

A vacuum cleaner fan assembly consisting of a compressor and an electric motor. A diffuser housing is provided, comprising a ring of guide blades constituting a radial diffuser in which ducts are provided for bypassing the air in the axial direction. The guide blades are supported by sealing means between the housing and an appropriate lid.

United States Patent [191 Keimpema et al.

1451 Feb. 12, 1974 1 1 VACUUM CLEANER FAN ASSEMBLY [75] Inventors: Keimpe Klaas Keimpema, Drachten;

Klaas Vonk, Hoogeveen, both of Netherlands [73] Assignee: U.S. Philips Corporation, New

York, NY.

[22] Filed: Oct. 1, 1971 211 Appl. No; 185,759

[30] Foreign Application Priority Data Oct. 3, 1970 Netherlands 7014555 [52] US. Cl 417/423 A, 415/211, 417/424 [51] Int. Cl. F04b 17/00, FO4d 29/44 [58] Field of Search 415/199 A, 501; 417/423, 417/424, 423 A 2,486,619 'lroxlcr 417/423 A 1 H1949 3,116,696 1/1964 Deters 415/199 A 3,158,295 11/1964 McConughy 1. 415/199 A 3,265,001 8/1966 Deters 415/501 3,288,074 11/1966 Hall 415/199 A 3,477,384 11/1969 Hlinka 415/501 FOREIGN PATENTS OR APPLICATIONS 413,887 7/1934 Great Britain 415/199 A 906,894 8/1956 Germany 415/199 A 342,065 1/1931 Great Britain 415/199 A Primary ExaminerHenry F. Raduazo Attorney, Agent, or Firm-Frank R. Trifari [5 7] ABSTRACT A vacuum cleaner fan assembly consisting of a compressor and an electric motor. A diffuser housing is provided, comprising a ring of guide blades constituting a radial diffuser in which ducts are provided for bypassing the air in the axial direction. The guide blades are supported by sealing means between the housing and an appropriate lid.

1 Claim, 8 Drawing Figures PAIENIEBFEBI 3'. 79 1.772

SHEEI 1 BF 5 I N VENTOKS KEIMPE K. KEIMPEMA KLAAS VONK Agent PATENIEB FEB 1 2 I974 saw 2 nr 5 12 s 11 Fig.3

INVENTORS KEIMPE K.KEIMPEMA KLAAS VONK PMENTEB FEB I 21974 SHEET 3 0F 5 VACUUM CLEANER FAN ASSEMBLY The invention relates to a vacuum cleaner fan assembly consisting of a compressor and an electric motor for driving this compressor. The compressor comprises an impeller which is mounted on the motor shaft and which is surrounded by a ring of guide blades constituting a radial diffuser.

In the construction of vacuum cleaners it is important that the fan assembly be constructed such that its dimensions are as small as possible, that it consists of a minimum number of components which can be inexpensively produced in mass manufacture, and, of course, that it offers optimum performance. So far, this object has only been partly achieved. For example, until now it has appeared to be almost impossible to manufacture a fan assembly having both an acceptable cost price and efficiency, and in particular it has been impossible to provide the compressor in an acceptable manner with diffuser means which are very desirable for flow-technical reasons in view of the important efficiency increase which they may give.

An attempt to a solution to the said problem is proposed in U.S. Pat. No. 3,263,909. The diffuser construction described therein, however, is so bulky and comprises so many components that its use can be contemplated only for central vacuum cleaning systems and industrial vacuum cleaners. The proposed solution is not suitable for use in domestic vacuum cleaners.

The present invention offers a solution to this problem by providing a construction which is suitable for use in domestic vacuum cleaners, and is characterized in that the guide blades are situated in a diffuser housing in which ducts are provided for bypassing, mainly in the axial direction, the air exhausted from the guide blades.

The diffuser housing is preferably constructed such that the guide blades and the housing form one assembly. This assembly can be made, for example, by injection moulding of a synthetic resin.

A further, considerably greater improvement is achieved in an embodiment which is characterized in that a lid is provided at one axial side of the housing, means being present at said side for supporting the guide blades.

It is thus possible to make the construction of the guide blades significantly thinner than has been considered possible so far. This implies that the inner diameter of the ring of guide blades can be chosen to be much smaller, thus approaching the outer diameter of the impeller. much more closely without the disadvantages thereof becoming manifest in an inconvenient manner. Furthermore, this enables the outer diameter of the fan assembly to be reduced even further which, in conjunction with the decreased diameter of the impeller permitted by the use of the diffuser, results in the fact that this diameter need not be larger than has been common practice thus far for fan assemblies without a ring of diffuser blades. As the impeller alone need no longer produce the desired pressure difference, because part thereof is already effected in the diffuser, the impeller may be designed, while maintaining the same motor power, for a larger displacement of air by increasing the height of the blades in the axial direction. This becomes manifest as the increased efficiency of the fan assembly. This increased blade height must, of course, also be applied to the diffuser blades. According to the invention this is possible without giving rise to annoying vibration phenomena.

According to a further embodiment of the invention it appeared advantageous when the said supporting means form part of the lid.

It was surprisingly found that the supporting means can be constructed very simply and inexpensively when, according to a further embodiment of the invention, they consist of a ring of elastic material which also serves for sealing the housing.

It is obvious that by application of one or more of the proposed steps according to the invention, it will be possible in many cases to use a single-stage compressor where so far a multi-stage compressor had to be chosen.

However, if a multi-stage compressor is to'be used after all, it is advantageous to take one or more of the described steps for each stage.

In order that the invention may be readily carried into effect, some embodiment thereof will now be described in detail, by way of example, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a side elevation of a single-stage vacuum cleaner fan assembly according to the invention,

FIG. 2 is a front view of the diffuser housing used therein,

FIG. 3 is a cross-sectional view thereof taken on the line III-III in FIG. 2, and of the lid used therewith,

FIG. 4 is a front view of a diffuser housing in another embodiment,

FIG. 5 is a sectional view thereof taken on the line VV in FIG. 4,

FIG. 6 is a front view of a lid for the housing shown in FIGS. 4 and 5,

FIG. 7 is a perspective and partly sectional drawing of this diffuser housing, and

FIG. 8 is a front and sectional view of a multi-stage vacuum cleaner fan assembly according to the invention.

' The single-stage vacuum cleaner fan assembly shown in FIG. 1 comprises a motor which is surrounded by a housing 1 and a compressor consisting of an impeller which is rigidly connected to the motor shaft and which rotates in a diffuser housing 2. This housing is closed by a lid 3 in which the inlet aperture for the air is situated.

The difiuser housing 2 is shown in FIGS. 2 and 3. It comprises a bottom plate 4 connected to the motor housing and provided with an aperture 5 through which the motor shaft can extend, a central space 6 in which the compressor impeller can rotate, and a mainly cylindrical outer wall 7.

A number of blades Sis provided on the inner side of this wall 7, each of the said blades acting as a guide blade over the portion denoted by A near a blade, and constituting, in pairs over the portion denoted by B a diverging duct in which diffusion occurs. For bypassing the air in the direction of the motor there are provided the wall portions 9, extending to the rear in FIG. 2 at an angle with respect to the plane of the drawing, as can also be seen in FIG. 3 in the two different sectional views taken on the line III-III in FIG. 2. The air can then depart in the axial direction through the apertures 10 which extend as far as below the wall portions 9.

For closing the ducts formed by the blades 8, the lid 11 shown in FIG. 3 is provided in this embodiment. This lid is provided with the central suction aperture 12.

Near the outer edge a ring 13 of an elastic material is situated between the diffuser housing and the ring, said ring not only providing the closing of the ducts, but also, as was surprisingly found, serving excellently for retaining the thin ends 14 of the blades 8. Consequently, these blades can be made much thinner without the risk of breaking due to vibrations or other causes. For the same reasons the ring 13, preferably made of a soft rubber, also permits the diffuser housing 2 to be higher, thus enabling a larger height of the blades 8. As already described, this offers an important improvement of the performance of the fan assembly.

The embodiment of the diffuser housing 2 shown in FIGS. 4, 5 and 7 and the associated lid shown in FIG. 6, is a simplified embodiment of the one previously described. In the Figures, corresponding components are denoted by the same references as in FIGS. 2 and 3. The same guide blade and diffuser portions A and B of the guide blades 8 can be recognized, and apertures 10 for discharging the air are provided in the bottom plate 4, the shape of which is denoted by broken lines in FIG.

The housing 2 is provided with a fitting rim 18 in which the lid 11 fits. This lid has the shape of a flat plate which is provided with a raised portion 15 of a shape such that it fits in the spaces between the blades 8, thus being capable of closing the ducts formed by these blades. In this portion 15 gaps 16 are recessed, in which the free portions of the blades 8 fit; it is thus possible to obtain the same effect as with the ring 13 in the previous embodiment. It is advantageous if the erect walls of the raised portion 15 are slightly tapered.

Finally, FIG. 8 shows another embodiment in which two identical diffuserhousings 2 according to the invention are used in a two-stage compressor unit, the air being sucked in through the motor and following the path denoted by arrows.-

The construction of the diffuser housings 2 is fully identical to that of the previously described housings.

It is obvious that the described diffuser housings can be provided at the exhaust .side of the air with guide blades for guiding the exhaust air. Such blades can be situated, for example, at the area denoted by 17 in FIG. 3.

We claim:

1. A fan assembly for a vacuum cleaner comprising a fan housing, an electric motor within said housing, a compressor formed by an impeller with said housing secured to the output shaft of said motor, a unitary diffuser housing coupled with said fan housing said diffuser including a plurality of guide blades carried on said diffuser housing on one side thereof forming a radial diffuser surrounding said impeller, a plurality of axial ducts in said diffuserhousing for axially bypassing air exhausted from said guide blades out that side of said diffuser carrying said guide blades and, a lid provided on the side of the diffuser opposite said guide blades, said guide blades having free axial ends, and a support ring carried by said lid for supporting said free axial ends of said guide blades and for sealing said housing. 

1. A fan assembly for a vacuum cleaner comprising a fan housing, an electric motor within said housing, a compressor formed by an impeller with said housing secured to the output shaft of said motor, a unitary diffuser housing coupled with said fan housing said diffuser including a plurality of guide blades carried on said diffuser housing on one side thereof forming a radial diffuser surrounding said impeller, a plurality of axial ducts in said diffuser housing for axially bypassing air exhausted from said guide blades out that side of said diffuser carrying said guide blades and, a lid provided on the side of the diffuser opposite said guide blades, said guide blades having free axial ends, and a support ring carried by said lid for supporting said free axial ends of said guide blades and for sealing said housing. 